Diagnosis Start Here

START OF DIAGNOSIS
To assess a Tiptronic transmission for which complaints have been received, the information about the fault and the fault occurrence should be as complete as possible.

To avoid extra damage during test drives or faulty diagnosis results, the following items must be checked and corrected (if required) prior to the test drive:

-. Read out fault memory with System Tester 9288 and correct fault.
- Check that battery, connectors, and ground points are O.K.

- External damage, leaks at transmission (ATF leaks) or final drive (hypoid oil loss), disconnected cables.

- ATF level in transmission correct, fluid is neither dirty nor does it leave a burning smell. If ATF is dirty or if it leaves a burning smell, it is recommended to replace the Tiptronic transmission if complete removal of the dirt residues cannot be ensured. In addition, the coolant lines and the cooler must be flushed.

- Engine operation, full opening of throttle when accelerator is in full-throttle position.

NOTE:
- If a system fault occurs, the Tiptronic system shifts into a reduced driving program. The warning lamp comes on and the automatic system shifts to 4th gear, irrespective of the selector lever position.

- As 4th gear establishes a rigid connection between engine and final drive, you must shift to "N" at a speed of about 30 kph to prevent the engine from stalling. When the vehicle has stopped, turn the engine off.

- When you start the engine again, only 2nd gear and reverse are available.

CAUTION: The reverse gear interlock monitor is inoperative. Do not shift into "R" while the vehicle is in motion.

The test drive
The test drive should be used to check if the customer complaint situations actually occur when the vehicle is driven. It is actually preferable to have the customer drive the car and to check for any potential faults, malfunctions or even for incorrect operation by the driver.

Check all functions of the transmission during the test drive:
^ All shifts, including in kickdown position in the automatic gate, as well as shifts in the manual gate
^ Various driving speeds
^ Driving in reverse (uphill if possible)
^ Stall speed

Make your diagnosis using the "Troubleshooting the Tiptronic transmission" section and determine the type of repair required.

This diagnosis plan is based on the fault memory contents. If no fault is stored although a malfunction is present, the troubleshooting plan for the mechanical/hydraulic section should be used. Troubleshooting requires that the person performing the tests:
^ is familiar with the location of components, operation and technical relationships of the systems being tested (refer to Model Information)
^ is able to read and evaluate Porsche wiring diagrams
^ knows the functions of circuits and relays
^ is capable of using testers such as oscilloscope, voltmeter, ohmmeter and ammeter, as well as of evaluating the test results.

Important:
The fault text displayed does not necessarily indicate a defect in this component, but may also refer to a fault in the corresponding control unit and the wiring (paths) between the component and the control unit.

Before reading out the fault memory, do not try to locate faults by disconnecting plugs etc. while the engine is running as this may be stored as a fault in the fault memory.

Note for System Tester 9288
If the tester display shows Fault not present, this may indicate:
^ Fault did not exist at the time of testing (e.g. in the case of loose connections)
Remedy: Visual inspection of path
^ In addition, in the case of a loose connection, the + symbol is displayed. Ex....... not present +
Remedy: Visual inspection of path
^ The conditions under which the fault is tested do not correspond to the conditions under which the fault occurred.
Remedy: Conform with the conditions displayed on the tester

Signal unplausible
The signal of the monitored component is not within the tolerance range of the value preset in the control unit.

Notes on the counter shown on the tester display
The first time a malfunction occurs, the counter is always set to 50. If the value is lower than 50, the difference between 50 and the value shown is the number of starts with the test condition fulfilled and without errors. When the value reaches zero, the error path is deleted in the control unit. If the error occurs again when the counter is less than 50, the counter is again set to 50. If the counter is above 50, the difference between the number shown and 50 is the number of loose contacts which have occurred. Even if the figure shown is above 50, the counter is still reduced by 1 until it reaches zero for each start with the test conditions fulfilled.